Abstract：Aiming at the problem of low measurement accuracy of triangular thin-walled weir open channel flowmeter when used at non-fixed points, based on the uncertainty pre-assessment results, it is proposed to use curve fitting instead of linear interpolation to calculate the flow coefficient, and a digital output magnetostrictive water level sensor is used to measure the water head, which significantly reduces the uncertainty items that contribute more to the original method. The frequency sampling method is improved based on the Froude's similarity criterion, which improves the accuracy level of the measurement results. The uncertainty of the measurement method is improved from 1.6% to 0.56%. The calibration experiments of the triangular thin-walled weir open-channel flowmeter are carried out by the standard meter method open-channel flow rate standard device, and the experimental results show that the measurement error is reduced from 2% to less than 1% after the improved method.
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GAO Ming,GUO Hui,JIA Zhizhuo. Optimization of Flow Measurement Uncertainty in Open Channel with Triangular Thin-walled Weir Based on Data Fitting Method. Acta Metrologica Sinica, 2024, 45(9): 1348-1352.
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2024, Vol. 45 
